JPH0361753B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a support used in a lithographic printing plate, which is formed by subjecting the surface of a roughened aluminum alloy plate to an anodic oxidation film treatment and further coating a photosensitive substance. The present invention relates to a method for producing an aluminum alloy lithographic printing support that has a uniformly roughened surface through surface roughening treatment and has excellent fatigue strength, thermal softening properties, and printability. Conventionally, what has been widely used as a lithographic printing plate is an aluminum plate that has been subjected to surface treatments such as roughening treatment and anodic oxidation coating, and a photosensitive substance is coated on it, and the so-called PS plate that is dried is subjected to image exposure. ,developing,
This is a printing plate obtained by performing a plate-making process such as washing and lacquering. The undissolved photosensitive layer resulting from this development process forms an image area, and the area where the photosensitive layer is removed and the aluminum surface underneath is exposed is hydrophilic.
It is a well-known fact that it becomes a water receiving area and forms a non-image area. Generally, aluminum plates are used as supports for lithographic printing plates, which are lightweight and have excellent surface treatment properties, workability, and corrosion resistance. pure
Al), JIS1100 (Al-0.05~0.20 wt% Cu alloy),
JIS3003 (Al-0.05~0.20wt%Cu-1.5wt%Mn
This is an aluminum alloy plate with a thickness of 0.1 to 0.8 mm, such as aluminum alloy), and the surface is roughened by one or a combination of mechanical, chemical, and electrochemical methods. The surface is roughened, and then preferably subjected to anodic oxidation treatment. Specifically, an aluminum lithographic printing plate that has been sequentially subjected to mechanical roughening treatment, chemical etching treatment, and anodized film treatment as described in JP-A-48-49501, or JP-A-51-61304. Aluminum lithographic printing plates were subjected to the chemical etching treatment and anodic oxide film treatment described in the publication, and the electrochemical treatment, post-treatment, and anodic oxide film treatment described in JP-A-54-146234. Aluminum lithographic printing plates that have been subjected to the electrochemical treatment, chemical etching treatment, and anodic oxide coating treatment described in Japanese Patent Publication No. 48-28123, or after mechanical roughening treatment. An aluminum lithographic printing plate subjected to the treatment described in Japanese Patent Publication No. 48-28123 is known. By appropriately selecting the photosensitive layer coated on such a support, it is possible to obtain up to 100,000 sheets of clear printed matter. However, there is a desire to obtain more printed matter from one printing plate (improvement of printing durability).
In such cases, after exposing and developing the PS plate using an aluminum alloy plate as a support in the usual way,
An effective method is to strengthen the image area by heat treatment at high temperatures (so-called burning treatment).
This method is described in detail in Japanese Patent Publication No. 44-27243 and Japanese Patent Publication No. 44-27244. The heating temperature and time for such a burning process depend on the type of resin forming the image, but
The usual range was 3 to 7 minutes at a temperature of 200 to 280°C. In recent years, burning treatments at higher temperatures and shorter times have been desired in order to improve printing durability and shorten burning treatment time.
However, when the conventionally used aluminum alloy plates are heated to a high temperature of 280°C or higher, the aluminum recrystallizes, resulting in an extremely low strength and a loss of stiffness, making the plates extremely difficult to handle. This results in disadvantages such as the inability to set the plate on the printing machine and the inability to register the colors of the plate in multicolor printing, and therefore a stable aluminum alloy plate with high heat resistance is desired. On the other hand, today, as printing speeds have increased due to advances in printing technology, the stress applied to the printing plate, which is mechanically fixed to both ends of the plate cylinder of the printing press, has increased, so if the strength is insufficient, this fixed part may be They often become deformed or damaged, causing problems such as printing misalignment, or the plates break (grip breaks) due to repeated stress applied to the folded portions of the printing plate, making printing impossible. Conventional JIS1050 aluminum alloy plates have uniform roughness and appropriate surface roughness through electrochemical roughening treatment, and stains in non-image areas during printing are less likely to occur, but fatigue resistance and heat softening resistance are inferior. In addition, conventional JIS3003 aluminum alloy plates have sufficient fatigue strength and heat softening resistance, but electrochemical roughening treatment does not provide a uniform or appropriate surface roughness, and furthermore, during printing, A drawback was that non-image areas were easily smeared. As described in JP-A-58-42745, the present inventor has developed an aluminum alloy plate for printing, which can obtain a uniform rough surface by roughening treatment and has excellent fatigue resistance, and a method for manufacturing the same. Developed, Mg0.05～
A printing aluminum alloy ingot consisting of 0.30% by weight, 0.03 to 0.30% by weight of Si, 0.15 to 0.40% by weight of Fe, and the balance being Al and normal impurities is soaked and hot rolled, and the area reduction rate is We have proposed a method for manufacturing aluminum alloy plates for printing, which is characterized by applying cold rolling of 70% or more and then low-temperature annealing at a temperature of 150 to 250°C for 1 hour or more. However, in recent years, the quality required for printing plates has improved, and specifically, it is desired that non-image areas become less stained during printing, and further improvements in this respect are required. In order to prevent stains in non-image areas during printing, it is important to improve the water retention of non-image areas, and for this purpose roughening treatment,
In particular, it is necessary to obtain better uniformity of the roughened surface than conventionally through electrochemical surface roughening treatment. Therefore, the object of the present invention is to have sufficient fatigue strength and heat softening resistance as a printing plate, and to obtain a uniform rough surface and appropriate surface roughness by roughening treatment, especially electrochemical roughening treatment. An object of the present invention is to provide a support for an aluminum alloy lithographic printing plate that does not easily stain non-image areas during printing. As a result of various studies regarding this, the present inventors found that Mg0.05~0.30% by weight, Si0.03~0.
0.30wt%, Fe0.15~0.40wt%, Cu0.05wt%
After soaking an aluminum alloy ingot, the balance of which is Al and normal impurities, it is hot rolled or cold rolled after hot rolling and intermediate annealed, followed by a final cold rolling with an area reduction of 70% or more. It has been found that an aluminum alloy plate has the ability to achieve the above objects by rolling and then temper annealing at a temperature of 250 to 350°C for 120 seconds or less in a continuous annealing furnace. The reason why the composition of the aluminum alloy ingot is limited as described above in the present invention is as follows. Mg is added for the purpose of improving the strength and fatigue resistance without adversely affecting plate surface roughening treatment and printing suitability. Mg is mostly solid dissolved in Al and improves strength and fatigue resistance, but Mg is not included. This is because if the amount is less than 0.05% by weight (hereinafter, % by weight will simply be referred to as %), the effect will be small, and if it exceeds 0.30%, the uniformity of the roughened surface in the surface roughening treatment will deteriorate. Fe is added to further improve fatigue strength. It forms intermetallic compounds, refines crystal grains, and makes the structure uniform. However, if it is less than 0.15%, the effect is small, and if it is less than 0.40%
This is because if it exceeds this, the uniformity of the rough surface in the roughening treatment and the printability will deteriorate. Si 0.03~0.30
The reason for this is that if it is less than 0.03%, the strength will decrease, and if it exceeds 0.30%, the uniformity of the roughened surface after electrochemical roughening will deteriorate and the corrosion resistance will also decrease. The reason for limiting Cu to 0.05% or less is that it is considered an impurity.
This is because if the Cu content exceeds 0.05%, pits tend to become coarse in electrochemical surface roughening treatment, and the stain resistance of non-image areas of the printing plate deteriorates. The impurities contained in the aluminum alloy constituting the aluminum alloy plate for lithographic printing in the method of the present invention do not impair the object of the present invention, as long as they are at the level of impurities contained in commercially available Al ingots. That is, Mn 0.05% or less, Cr 0.05% or less,
There is no particular problem if Zn is 0.05% or less. In addition, when manufacturing ingots, Ti and B, which are usually used as crystal refining agents, contain less than 0.03% of Ti and 0.01% of B.
The following additions are effective in uniformly refining the alloy structure. As described above, in manufacturing the aluminum alloy plate for lithographic printing of the present invention, an aluminum alloy ingot having the above composition is subjected to soaking treatment to dissolve Mg and impurities in solid solution, and also to dissolve a part of Fe in solid solution. Disperses intermetallic compounds uniformly and finely.
This soaking treatment is preferably carried out at a temperature of 450 to 600°C for 3 hours or more. Next, this is hot rolled by a conventional method, or after hot rolling, cold rolling and intermediate annealing are performed. It is appropriate to perform hot rolling at a temperature of 550 to 200°C, and if necessary, intermediate annealing after hot rolling may be performed at 300 to 400°C for 2 to 5 hours or in a continuous annealing furnace at 400 to 550°C for 120°C. It is desirable to do this in less than a second. The plate thus obtained is finally cold rolled so that the reduction in area is 70% or more. In this final cold rolling, the Fe intermetallic compound is dispersed, and the crystal structure becomes uniform. If the area reduction rate is less than 70%, the intermetallic compound will not be sufficiently dispersed and the crystal structure will be non-uniform, making it impossible to obtain a uniformly roughened surface in the surface roughening treatment. The thus obtained rolled plate is rapidly annealed in a continuous annealing furnace at a temperature of 250 to 350°C, preferably 270 to 350°C for 120 seconds or less. Temper annealing under these conditions gives the rolled plate appropriate mechanical properties.
In other words, it provides appropriate strength and elongation, improves heat softening resistance, and at the same time suppresses the precipitation of fine intermetallic compounds of Al and Fe as much as possible, resulting in a uniform pit shape and appropriate surface roughness. This is to improve the water retention and stain resistance of non-image areas during printing. The temper annealing conditions are
If the temperature is below 250℃ or above 350℃, or if the treatment time exceeds 120 seconds, sufficient fatigue resistance and heat softening resistance may not be obtained, or the surface may become rough due to the precipitation of intermetallic compounds of Al and Fe. The shape of the pits also becomes non-uniform, and the water retention and stain resistance of non-image areas decrease. The aluminum alloy plate for lithographic printing of the present invention produced in this way has been roughened by surface roughening treatment.
A more uniform pit shape and appropriate surface roughness can be obtained than JIS1050 aluminum alloy, which not only improves water retention and stain resistance in non-image areas, but also has excellent fatigue strength and heat softening resistance. It will be done. Next, a method for surface treating a lithographic printing plate support according to the present invention will be explained in detail. The graining methods used in the present invention include an electrochemical graining method that electrochemically grains the grain in a hydrochloric acid or nitric acid electrolyte, a wire brush graining method that scratches the aluminum surface with a metal wire, and an abrasive ball and abrasive agent that polishes the aluminum surface. Mechanical graining methods such as the ball grain method, which grains the surface, and the brush grain method, which grains the surface using a nylon brush and abrasive, can be used, and any of the above graining methods can be used alone or in combination. You can also do it. Aluminum grained in this way is
Chemically etched with acid or alkali. When an acid is used as an etching agent, it takes a very long time to destroy the fine structure, which is disadvantageous in industrial application of the present invention, but this can be improved by using an alkali as an etching agent. The alkaline agents preferably used in the present invention include caustic soda, soda carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide, etc., and the preferred ranges of concentration and temperature are 1 to 50% for each. , 20~100℃
Conditions are preferable such that the amount of dissolved Al is 5 to 20 g/m ² . After etching, pickling is performed to remove any dirt (smut) remaining on the surface. The acids used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and hydrofluoric acid. In particular, for smut removal treatment after electrochemical surface roughening treatment, it is preferable to contact with 15 to 65% by weight sulfuric acid at a temperature of 50 to 90°C as described in JP-A-33-12739. and the alkali etching method described in Japanese Patent Publication No. 48-28123. The aluminum plate treated as described above can be used as a support for a lithographic printing plate, but it is preferable to further perform treatments such as anodization coating treatment and chemical conversion treatment as necessary. The anodic oxidation treatment can be performed by a method conventionally used in this field. Specifically, sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid,
When a direct or alternating current is passed through aluminum in an aqueous or non-aqueous solution of benzenesulfonic acid or the like or a combination of two or more of these, an anodized film can be formed on the surface of the aluminum support. The treatment conditions for anodic oxidation vary depending on the electrolyte used, so they cannot be determined unconditionally.
Generally, the concentration of electrolyte is 1~80%, and the temperature of the electrolyte is 5~70%.
°C, current density 0.5~60 ampere/ ^dm2 , voltage 1~
A range of 100V and electrolysis time of 10 to 100 seconds is appropriate. Among these anodic oxide film treatments, the method of anodizing at high current density in sulfuric acid used in the invention described in British Patent No. 1412768 and the method described in U.S. Patent No. 3511661 are particularly Preferred is the method of anodic oxidation using phosphoric acid as an electrolytic bath. The anodized aluminum plate may be further treated by immersion in an aqueous solution of an alkali metal silicate, such as sodium silicate, as described in U.S. Pat. As described in US Pat. No. 3,860,426, a subbing layer of hydrophilic cellulose (such as carboxymethylcellulose) containing a water-soluble metal salt (such as zinc acetate) may also be provided. On the lithographic printing plate support according to the present invention,
A photosensitive lithographic printing plate can be obtained by providing a photosensitive layer conventionally known as a photosensitive layer of a PS plate,
The lithographic printing plate obtained by plate-making this has excellent performance. The composition of the photosensitive layer includes the following. Photosensitive layer consisting of a diazo resin and a binder Reaction of a diazonium salt disclosed in the specifications of U.S. Pat. A condensation product of diphenylamine-p-diazonium salt and formaldehyde (so-called photosensitive diazo resin) is preferably used. Other useful condensed diazo compounds are disclosed in Japanese Patent Publication No. 49-48001,
It is disclosed in publications such as No. 49-45322 and No. 49-45323. These types of photosensitive diazotized compounds are usually obtained in the form of water-soluble inorganic salts and can therefore be coated from aqueous solution. Alternatively, these water-soluble diazo compounds can be reacted with an aromatic or aliphatic compound having one or more phenolic hydroxyl groups, sulfonic acid groups, or both, by the method disclosed in Japanese Patent Publication No. 1167/1983. It is also possible to use substantially water-insoluble photosensitive diazo resins which are reaction products. Also, JP-A-56-
It can also be used as a reaction product with hexafluorophosphate or tetrafluoroborate as described in JP 121031. In addition, diazo resins described in British Patent No. 1312925 are also preferred. Photosensitive layer made of O-quinonediazide compound Particularly preferred O-quinonediazide compound is O-quinonediazide compound.
- naphthoquinone diazide compounds, such as U.S. Patent Nos. 2766118, 2767092,
No. 2772972, No. 2859112, No. 2907665,
Same No. 3046110, Same No. 3046111, Same No. 3046115
No. 3046118, No. 3046119, No. 3046119, No. 3046118, No. 3046119, No.
No. 3046120, No. 3046121, No. 3046122,
Same No. 3046123, Same No. 3061430, Same No. 3102809
No. 3106465, No. 3635709, No. 3635709, No. 3106465, No. 3635709, No.
It is described in numerous publications including the specifications of No. 3647443, and these can be suitably used. Azide compound and binder (photosensitive layer made of a polymer compound) For example, the specifications of British Patent No. 1235281 and British Patent No. 1495861, and JP-A-51-32331, British Patent No. 51
In addition to the composition comprising an azide compound and a water-soluble or alkali-soluble polymer compound described in Japanese Patent Publication No. 50-5102 and Japanese Patent Application Laid-open No. 50-50-
Included are compositions consisting of a polymer containing an azide group and a polymer compound as a binder, which are described in the following publications: No. 84302, No. 50-84303, and No. 53-12984. Other photosensitive resin layers For example, polyester compounds disclosed in JP-A-52-96696, British Patent No. 112277
No. 1313309, No. 1341004,
Included are polyvinyl cinnamate resins described in U.S. Pat. No. 1,377,747 and other specifications, and photopolymerizable photopolymer compositions described in U.S. Pat. The amount of photosensitive layer provided on the support is approximately
It ranges from 0.1 to about 7 g/m ² , preferably from 0.5 to 4 g/m ² . After the PS plate is image exposed, a resin image is formed by processing including development using conventional methods.
For example, in the case of a PS plate having the photosensitive layer made of a diazo resin and a binder, after image exposure,
Unexposed portions of the photosensitive layer are removed by development to obtain a lithographic printing plate. Also has a photosensitive layer
In the case of a PS plate, after image exposure, the exposed portion is removed by developing with an alkaline aqueous solution to obtain a lithographic printing plate. Hereinafter, it will be explained in more detail based on Examples. Example 1 Aluminum alloys No. 1 to No. 1 with the compositions shown in Table 1.
No. 12 was melted and cast, and both sides were face-milled to obtain an ingot with a thickness of 350 mm and a length of 2000 mm, which was soaked at a temperature of 550°C for 10 hours. This was hot rolled at a temperature of 450 to 250°C to a plate thickness of 4.5 mm, and then further cold rolled to a plate thickness of 0.3 mm (area reduction rate 93.3%). These are continuously passed through an annealing furnace and subjected to temper annealing at 300℃ for 30 seconds.
An aluminum alloy plate for lithographic printing was manufactured. Next, No. 1 to No. 12 aluminum alloy rolled plates and
No.13 (0.30mm JIS1050-H18 aluminum alloy), No.14 (0.30mm JIS1100-H16 aluminum alloy), and No.15 (0.30mm JIS3003-H14 aluminum alloy) in a suspension of pumice stone and water. After graining with a rotating nylon brush, etching was performed using a 20% aqueous solution of caustic soda so that the dissolved amount of aluminum was 5 g/m ² . After thoroughly washing with running water, pickling was carried out with a 25% nitric acid aqueous solution, and the substrate was prepared by washing with water. The substrate prepared in this way was processed as described in Japanese Patent Application Laid-open No. 146234/1983.
Current density 20A/in an electrolytic bath containing 0.5-2.5% nitric acid
AC electrolysis was carried out at dm ² or more. Continued with 15% sulfuric acid
After cleaning the surface by immersing it in an aqueous solution at 50℃ for 3 minutes, it was soaked in an electrolytic solution containing 20% sulfuric acid as a main component at a bath temperature of 30℃.
An oxide film of 3 g/dm ² was provided. The following photosensitive layer was provided on the sample prepared in this manner so that the dry coating amount was 2.5 g/m ² . Ester compound of naphthoquinone-1,2-diazido-5-sulfonyl chloride, pyrogallol, and acetone resin (described in the Examples of US Pat. No. 3,635,709) 0.75 g Cresol novolak resin 2.00 g Oil Blue #603 ( Orient Chemical Co., Ltd.) 0.04g Ethylene dichloride 16g 2-methoxyethyl acetate 12g The photosensitive lithographic printing plate obtained in this way was brought into close contact with the transparent positive image and was exposed to PS light from a distance of 1m [Light source of Toshiba metal halide lamp MU2000-2-OL type 3KW] (sold by Fuji Photo Film Co., Ltd.) for 30 seconds, immersed in a 5% by weight aqueous sodium silicate solution for about 1 minute to develop, washed with water, and dried to obtain Sample No. 1. ~No.15 was created. Tests were conducted on the uniformity of the electrolytically etched rough surfaces, stains in non-image areas, fatigue strength, and thermal softening properties of Samples No. 1 to No. 15 prepared in this way, and the results are shown in Table 1. (Test method) (1) Uniformity of electrolytically etched rough surface The surface condition was observed using a scanning electron microscope, and the uniformity of pits was evaluated. expressed. (2) Staining in non-image areas Staining in non-image areas was evaluated using the offset printing machine KOR, and excellent results were marked with ○, good results were marked with △, and poor results were marked with ×. (3) Fatigue strength Cut out a test piece with a width of 20 mm and a length of 100 mm from each sample, fix one end to a jig, bend the other end upward at an angle of 30°, return it to its original position, and The number of times until breakage was measured, with 1 time being counted as one time. (4) Thermal Softening Properties The sample was heated at 300° C. for 7 minutes in a Burnig Processor 1300 (a Burnig Processor manufactured by Fuji Photo Film Co., Ltd. with a 12 KW heat source). After cooling, a JIS No. 5 test piece was created and subjected to a tensile test.
The 0.2% proof stress value was measured.

[Front] Printing board


JIS1100−H16 14 0.01 0.13 0.53
0.12 〃 〃 ×
JIS3003−H14 15 0.00 0.24 0.59
0.13 0.99 〃 ×

[Front] Printing board

JIS1100−H16 14 ×
230 190 15.2 7.0
JIS3003−H14 15 ×
680 490 14.8 13.5
As is clear from Table 1, the printing aluminum alloy plates No. 1 to No. 7 obtained by the method of the present invention have uniformity of the electrolytically etched rough surface, stain resistance of non-image areas during printing, and fatigue resistance. , satisfies all properties in terms of heat softening properties, and exceeds conventional JIS1050 and 1100.
and 3003. On the other hand, aluminum alloy plates No. 8 to 12 with comparative alloy compositions outside the composition range of aluminum alloy plates in the method of the present invention have poor rough surface uniformity, staining of non-image areas during printing, fatigue strength, and heat softening resistance. It can be seen that one of the characteristics is inferior. That is, No. 8, which has a low Mg content, has good rough surface uniformity and stains in non-image areas during printing, but has poor fatigue strength and heat resistance, and No. 9, which has a high Mg, Si, and Fe content. No. 11 had good fatigue strength and heat resistance, but was poor in the uniformity of the rough surface and in the staining of non-image areas during printing. Also contains a lot of Cu
No. 12 had poor uniformity of the rough surface and poor stain resistance in non-image areas during printing. Example 2 Using the alloy ingot No. 2 in Table 1 in Example 1, soaking treatment was performed at a temperature of 560°C for 8 hours,
This was hot rolled at 550 to 300°C to a thickness of 3.0 to 8.5 mm, then cold rolled under various conditions shown in Table 2 (○ in the table indicates intermediate annealing), followed by temper annealing and printing. manufactured aluminum alloy plates for The aluminum alloy plates for printing produced in this way were surface-treated in the same manner as in Example 1, and plate-formed under the same conditions to create samples Nos. 16 to 27. For comparison, a plate was made using the conventional JIS1050 (component No. 13 in Table 1) under the conditions shown in Table 2, and the plate was made in the same manner as above to prepare sample No. 28. These samples were subjected to the same tests as in Example 1, and the results are shown in Table 2.

【table】

[Table] As is clear from Table 2, the area reduction rate after hot working
Printing aluminum alloy plates No. 16 to No. 21 made by the method of the present invention are subjected to final cold working of 70% or more and then temper annealed in a continuous annealing furnace at a temperature of 250 to 350°C for 120 seconds or less. Both the uniformity of the rough surface and the contamination of the non-image area during printing were compared to printing plates (No. 26 and No. 27) manufactured under conventional temper annealing conditions (annealing in a batch furnace) and those with conventional composition and conventional preparation. Manufactured under high quality annealing conditions
Even better than JIS1050 printing plate (No.28),
The fatigue strength was over 60,000 cycles, and the thermal softening properties after burning at 300°C for 7 minutes were all over 12Kgf/mm ² in yield strength. Note that No. 16 to No. 19 are cases without intermediate annealing, and No.
No. 20 and No. 21 are cases in which intermediate annealing was applied, and the results were good in both cases. On the other hand, No. 22, which has a low area reduction rate, has good fatigue strength and heat resistance, but is inferior to the uniformity of the rough surface and staining of non-image areas during printing, and the temperature and time of temper annealing conditions are For No. 23 to No. 25, which are outside the range of
Equivalent to JIS1050, but inferior in either fatigue strength or heat resistance. In this way, the aluminum alloy plate produced by the method of the present invention has excellent rough surface uniformity equivalent to or better than that of conventional 1050 aluminum plates, is less prone to staining in non-image areas during printing, and has excellent fatigue strength and heat softening properties. This is sufficient, and it has remarkable effects as a lithographic printing plate that has all of these characteristics.

Claims (1)

[Claims] 1 Mg0.05-0.30% by weight, Si0.03-0.30% by weight,
Fe0.15~0.40wt%, Cu0.05wt% or less, the balance
After soaking an aluminum alloy ingot consisting of Al and normal impurities, hot rolling or cold rolling after hot rolling and intermediate annealing are performed, followed by final cold rolling with an area reduction of 70% or more, A method for producing an aluminum alloy lithographic printing plate support, which is then subjected to temper annealing at a temperature of 250 to 350°C for 120 seconds or less in a continuous annealing furnace.